View Full Version : Tiny bubbles

11-26-2012, 05:59 PM
I just finished putting the final coat of epoxy to fill the weave on the bottom and sides of my build. I now have a gazillion little tiny bubbles! These will have to be sanded out before I paint. I used a foam roller and the minimal amount of epoxy to fill the weave. Boat is in the basement with a temp of about 65 degrees F. Any advice to prevent this with my next build?

Robert W. Long
11-26-2012, 06:01 PM
I think I recall tipping lightly with a brush after rolling on the epo fill coat.

Gib Etheridge
11-26-2012, 06:14 PM
Roll and tip, every coat. Then tip again in 1/2 hour, repeat as necessary until it's too set up to tip.

It also helps to seal the wood with one coat rolled and tipped then sanded smooth first. When staple holes fill with resin the displaced air in the holes comes out and makes big bubbles.

If you find round white spots that's probably caused by the cloth bridging low spots. You can keep pushing them in with the plastic squeegee until it sticks, but they will often show through the varnish. Painting makes it all much easier.

Tiny Bubbles....A good name for the boat?

11-26-2012, 06:25 PM
If the material underwent any temperature change you can get bubbles in a finish, or epoxy.

have fun sanding!

11-26-2012, 06:39 PM

Ian McColgin
11-26-2012, 07:06 PM
Lots of things can start bubbles in epoxy, but I got otherwise unexplained bubbles the only time I used a foam roller. At various stages I use two hard plastic rollers, one with spreading grooves and one smooth, and flat plastic spatulas of varying widths with some notched and some smooth.

The notched or grooved units help spread the epoxy more or less evenly. The smooth units are for moving it a bit thinner and for forcing it into the fabric.

I actually get the epoxy on the surface either by brush or by pour, depending on the feel of it all.


11-26-2012, 08:54 PM
A probable cause was a rising temperature. The porous wood exudes bubbles as it warms.
Better to get the victim warm, apply the epoxy, turn down the heat. Robb White did this this in an extreme way and got good results. Maybe someone can find the article.

11-27-2012, 09:58 PM
"Finish coat"? This makes me think there's, prior coats on the hull. The cause is the foam roller. I use a bondo squeegee thingies. If you're better off using enough to allow you to wet out rapidly, and apply peelply to suck up the excess

wizbang 13
11-28-2012, 12:22 AM
That is why I prefer to use epoxy coating made for painting for priming, not so much the resin. It is a dam tricky job.